In the renovation of sewer tube systems it was previously necessary to exchange damaged sewer tubes with entirely new sewer tubes, which encompassed major costs and possibly troublesome digging work which additionally disturbs the surroundings. Today a newer method of renovation is applied more and more, provided that damaged sewer tubes have the required capacity, wherein the existing sewer tubes are provided in situ with a tube lining comprising a plastics lining which is, for example, formed from a plastics strip which is wound up and assembled inside the sewer tube by special methods and apparatus. It should be remarked that a plurality of accepted methods are known for renovating sewer tube systems by means of an inner lining.
A mandatory prerequisite for applying the new renovation method as mentioned is, at least if sewer systems are concerned which do not allow personal access, the development of small mobile TV cameras such that one may part inspect, prepare and measure up the existing sewer system precisely and part reestablish the positions, precisely as well, at which side openings must be formed again in the plastics lining.
More specifically the invention relates to an apparatus which is primarily developed for use in renovation of sewer tubes, for example, according to the method as mentioned above wherein a plastics liner is formed by winding up inside an existing sewer tube. Admittedly, apparatus are known which are meant to serve the same purpose; but to some extent these known apparatus are very clumsy and complicated in their construction and, consequently, they are rather costly. Furthermore the known apparatus for the purpose mentioned are so large that in practice they can only be used in relatively large sewer tubes.
EP-A-0 084 427 discloses an apparatus for use in renovating sewer tubes and comprising a cylindrical apparatus body adapted to be moved inside a tube in such a way that the position of the apparatus in the tube is known, and a motor-driven tool wherein the motor-driven tool is mounted on a carrier member which protrudes from an end portion of the apparatus body and is journaled so as to be rotatable with respect to the apparatus body around a longitudinal axis. Opposite the apparatus body, the carrier member comprises a lifting mechanism which is interposed between a free end of the carrier member and the tool in such a way that the tool on the latter can be moved diametrally within the tube. Furthermore this known apparatus comprises a turning motor which is interposed between the apparatus body and the rotatable carrier member.